Water Cooled Chillers are incorporated in large facility HVAC systems, primarily with greater than 300-400 ton loads. A chiller produces water, used by building space cooling equipment (Air Handlers, Fan Coils, etc.). Chillers remove heat from a circulating cold water loop and discharge that heat to the outside air through a cooling tower. Chiller efficiency is usually measured in terms of electrical use per ton of cooling (KW/ton).
Water cooled chillers include Reciprocating, Screw and Centrifugal; the latter are used in larger systems and are the most efficient (.50-.65 KW/ton).Older, less efficient, and obsolete refrigerant chillers will likely benefit from replacement. In general, chillers that operate more than 4,000 hours per year that are over 20 years old, greater than .70 KW/ton and/or utilize older refrigerants are good candidates for replacement. The older types of refrigerants, such as R-11 and R-12 (CFC containing), are no longer produced due to negative environmental impact and have thus become very expensive and difficult to obtain, making them definite candidates for replacement.
Chillers are rated at full load efficiency, application part load value (APLV), and integrated part load value (IPLV). The latter two values are generally more useful numbers to analyze because chillers operate primarily at part load conditions. When analyzing a new or replacement system calculating how the system will operate at part load expectations are critical in making the proper analysis.
If you have questions about chiller efficiency, contact a member of the ConServ team for more information. We can help you analyze operating cost, maintenance, and the type of refrigerants that are associated with a new, more efficient chiller. First cost is only part of the equation.
ConServ Building Services, LLC provides excellent commercial HVAC, refrigeration, plumbing, and general construction services to businesses across the Southeastern United States. To learn more about ConServ, visit www.conservonline.com.